Am I mad?

Or do I have too much time on my hands?

Well, probably a little of both.

A bit of history and a confession first, many years ago I used to be a 'rig doctor'.

Not your average run of the mill screwdriver expert, hey, I was a trained electronics engineer (I suppose I still am but I don't do that for a living any more) and I used to modify, repair and 'tune' (I hate that description) radios, from your average 27/81 40CH FM set all the way up to and over Somerkamps, Yaesu, Icoms and once upon a time some really lovely Israeli Military stuff that I'm still not really allowed to discuss.

The repairs were the bread and butter stuff which kept me in beer and cigs when I used to consume those things but I *really* enjoyed modifying radios, developing EPROM conversions, adding bands, making them do things they were never supposed to do essentially and I specialised in the Cybernet PLL02A chassis sideband rigs with the occasional Cobra, Uniden or President thrown in for good measure. 


So, digging around in my shed for some components, I found a pile of old rigs. Most are complete and working, one or two are donor scrappers and then there was the Cobra.

A PC-879AB Chassis Cobra 148GTL-DX.

Looking very sorry for itself.

A Cobra that I'd been given to repair almost 20 years ago.

Now, while I do sometimes put things to one side and forget about them, this particular Cobra's owner had a history of being a bad lad but somehow he managed to persuade me that it was essential he was 'on-air', being a soft touch, I lent him a mint Multimode 2 so he could be on air.

Which he sold.

For £30.

To say I was a bit pissed off was an understatement, so I kept hold of his Cobra and told him that once he got my radio back I would give his back to him.

Of course, I never saw the Multimode again and the Cobra was dumped in a corner of my workshop, I moved house, gave up on radio because I discovered computers, had kids, all that and forgot about it.

Until a few weeks ago when I found it in a very soggy box of old books.

It's definitely had it's day, it's very sorry for itself and had been hacked about by some screwdriver expert who knew enough that Cobra's have a Motorola PLL. Except, they don't, not all of them anyway. This one needs an MB8719 but someone has put an MC145106 in place. Obviously, it doesn't work.

So, what to do? Chuck it in the bin? Yeah, that's probably best.

Except, well, I'm an idiot. I've decided to resurrect it and have a little fun with it so, here, on these pages I hope I'm going to be able to document my efforts in getting this old lady back on air.

I've still got a load of old test equipment, meters, a 'scope, frequency counters and multimeters but I need a few new bits on this quest because, I've decided, back on air isn't good enough.

This radio is going to be something a bit special. Cosmetically, it's bloody ugly but the PCB? Looks pretty  good.

So, first order of business is to get it back up and running, transmitting on frequency then let's see where it goes after that.

Right, I've bored you enough with words now, some pictures so you get an idea of my folly. (note, this is pretty much as it came to me, no knobs, ratty front bezel, extra wires. Band switch missing, that was me, can't remember why but it was 20 years ago and the corrosion, yeah, my shed.)

Pretty nasty eh?

 Lovely faceplate. Might need a new bezel. Or not. I'm not really interested so much in the looks of this rig, I want function and if I can get that then I may put some effort into making it pretty.

 But, mostly complete and not actually too bad from an electronics point of view

 A couple of track cuts and bridges, not entirely sure those red, white, yellow and blue wires are meant to be there but there's a service manual I need to read...

 Ah, PC-879AB, it's a Cobra then.

 Umm, that's not right, at least not in this radio...

 And no loop crystals in two of the places they should be. Hmm. This thing has been modded, reckon there's a board missing.

A TIP32!!! It must be a Jentec! Oh, what? Yeah, ermm, I was fitting TIP42 and TIP32 regulator transistors  to Cybernet Export rigs and Cobras years ago and I'm not called John.

A BDX54C Darlington transistor. I'm going to have to ask my mum if I was called John.

All in, a bit sad and bedraggled. Next job, take out that MC145106P, power it all up and see if I get the relevant static voltages, life from the loop oscillator and other crystals (yeah, not the PLL one until I get an MB8719)

Next post, probably this weekend at some point, let's see if I can coax some life out of her.